Development and experimental validation of a transient 2D numeric model for radiant walls

Abstract

An experimental set-up consisting of a house like cubicle exposed to outdoor weather was used to validate a numerical model of a radiant wall. The 2D transient finite volume model used as inputs the indoor temperature, outdoor temperature, global solar radiation incident on a vertical surface, and temperature and flow of the supply water. The simulation results closely agreed with the temperature profiles and heat fluxes for the three studied orientations (East, South, and West). Furthermore, a parametric study was carried out with the radiant wall model, concluding that pipes spacing between 125 mm and 150 mm and depth between 45 mm and 65 mm minimized the temperature difference on the surface while maximizing the heat flux. Furthermore, a control strategy with shorter activation periods improved the heat transfer efficiency.

The work was partially funded by the Spanish government (ENE2015-64117-C5-1-R (MINECO/FEDER), ENE2015-64117-C5-3-R (MINECO/FEDER), and ULLE10-4E-1305). GREA is certified agent TECNIO in the category of technology developers from the Government of Catalonia. The authors would like to thank the Catalan Government for the quality accreditation given to their research group (2014 SGR 123) and the city hall of Puigverd de Lleida. This projects has received funding from the European Commission Seventh Framework Programme (FP/2007–2013) under Grant agreement Nº PIRSES-GA-2013-610692 (INNOSTORAGE) and from European Union's Horizon 2020 research and innovation programme under grant agreement Nº 657466 (INPATH-TES). Alvaro de Gracia would like to thank Ministerio de Economia y Competitividad de España for Grant Juan de la Cierva, FJCI-2014-19940.